I've been searching for the last 2 hours on both the rx7club and msefi websites and have come up empty handed. I need to know what wire goes where for the ignition coming from the megasquirt.
Which wires coming from the megasquirt hook up to the CAS? I know that 2 of the wires are grounds, but then there is one for the leading, and one for the trailing (I think).
Then, as for the coils, which wires coming from the megasquirt go to the negative sides of each of the 3 coils?
Lastly, do I just hook up the tach wire to the #1 trailing coil negative side?
All in all, I need to know where each of these 6 wires are coming from and which PIN number they are on the ECU, because I'm sort of lost on this. (Example: pin #__ is for the the CAS, pin#__ is for the the leading coil (-) side, etc.

I am using the MS-I 3.0 board, I am using the "stock" LM circuit because I will be cutting 2 teeth off of the CAS, and I have added the 3 4.7k ohm resistors to the LED's. Was I supposed to run wires from the LED's or something, or not? I'm just lost right now as to which wire from the ECU goes where for the ignition. And no, I am not using any extra boards, such as Error's board.

Thanks for your help in advance.
Regards,
Brian

 

One last thing:
My wiring kit tells me to use the 5 short black ground wires for pins 7 - 11 and the 5 long black ground wires for pins 12 - 16, which is what I did. But I noticed that on a different wire diagram, that there is also a ground wire for pin# 19. Should I switch one of the ones I have for pin# 19 or am I ok? If so, which one?
Also, can I use any of these ground wires for the negative side of the CAS or can I only use 1 specific one? Which one should I use?

Thanks,
Brian

 

Here's my connection sheet for an S4 with stock CAS.

 

All the info is actually in the FAQ, there are several diagrams which rex4life created that should be accurate for the signals to the ignitors.

For the CAS wiring, I will be posting a new diagram from rex4life as soon as I can, but basically his diagrams just got Ne+ and Ne- reversed, and G+/G- reversed.

 

Also, you don't need to run a wire from the negative lead of the coil to the megasquirt... the "tach" signal comes from the CAS, which should already be hooked up to the "tach" pin on the MS, and to one of the ground pins.

Also, you don't connect the MS to the negative side of any of the coils for firing them either... the MS gets connected to the ignitors... the ignitors still control the coils.

I strongly suggest you read the FAQ, then read it again, then read it again. The answers to everything you asked are there, and reading those should also help clear up your confusion.

 

How about I make it even more confusing:
From my "understanding", according to Muythaibxr's FAQ, pin#24 goes to the Ne(+) wire to the CAS, pin#7 goes to the Ne(-) and G(-) wires to the CAS, and as for the G(+) wire, I have absolutely no idea. Am I supposed to hook up a G(+) wire to the CAS then? I'm only using the single lm1815 built in circuit on my v3 board, with 2 teeth cut out of my CAS.

Then I read it again:
Do I HAVE to buy error*'s msns-extra board to make this work??

Now as for what Muythaibxr wrote:
"For both the v3 and v2.2 board, you'll want to put the 4.7Kohm resistors as detailed in my last post, and then you'll want to wire the negative lead of led 17 (the one closest to the serial port) to your leading ignitor's IGt wire (IGt-L). The negative lead of led 18 goes to the coil select wire on your trailing ignitor (IGs-T). Finally, the negative lead of led 19 will need to be wired to the IGt wire on the trailing ignitor (IGt-T)."

Am I supposed to run wires from these LED's? Or am I supposed to go off of a modified diagram that I have which states that:
pin#25 is for ign#1
pin#27 is for ign#2
pin#29 is for ign#3
pin#31 is for A-In (whatever the hell that is)

Now here's another one:
As for what Eagle7 posted in this thread about his diagram, his diagram reads:
pin#1 is a ground
pin#2 is a ground for G(-)
pin#3 is for G(+)
pin#4 is for IGt-L
pin#5 is for IGs-T
pin#6 is for IGt-T
pin#7 is for Ne(-)
pin#24 is for Ne(+)

Now, obviously I see where Ne(-), Ne(+), and G(-) go, but I still don't know about G(+). Maybe I'm just missing the fact that I HAVE to buy Error*s board, which I wasn't fully aware of that I HAD to buy.

One last thing:
Eagle7's diagram has wires for pins#1-6, whereas I do not. What's this all about?? I simply have ground wires for pins# 7-16. Am I supposed to switch something around?

Yes, I am new to this, but I just can't seem to find a simple answer to my question. I'll probably write a thread for newbie's once I'm done so that no one has to ask the same questions that I have. It's just that I can't seem to find a common diagram or response for what I need as you can see about my confusion from what I just typed above about the different "possibilities". Someone just please give me a straight answer, that's it.

Brian

 

There IS no straight answer... You can use whatever spare pins on the ms that you want to use, and you have to wire things internally on the MS to do that... keeping track of what you've done.

If you bought a pre-built wiring harness for your MS, then most likely whatever instructions it came with are confusing you.

You do NOT need an error* daughterboard or the G+/G- wires at all if you've cut 2 teeth out of the CAS.

What I do on my MS's for ignition outputs is choose any three of the spare pins (which have via's on the board inside the MS), and wire the negative leads of the LEDs to the vias for the 3 spare pins I selected... I keep notes on what I ran where, and then when I'm making the harness, I make sure I wire the proper pin on the MS to the proper wire on the ignitor.

Eagle7's diagram and instructions most likely assume you know that you have to do some wiring internally on the MS.

I don't have any idea what "modified diagram" you're using.

So to summarize:

1) you don't need your G wires at all if you're cutting teeth out of the CAS. Because of this, you don't need to get error*'s daughtercard... Even if you wanted to use the G wires, you wouldn't need error*'s daughtercard, you'd just need to build an lm1815 circuit in the proto area.
2) all the diagrams and pin numbers are confusing you because unless you've modified your MS internally, and actually run wires where they need to go to the vias for the spare pins on the DB37, none of those spare pins do anything.
3) There is no "straight answer" because you can do the internal wiring however you want.

Oh, and finally, the built-in vr sensor conditioner on the v3 board isn't an lm1815 circuit... it's a custom-designed circuit for this board utilizing an op-amp, some transistors and some other components, but not an lm1815 chip. Just saying that now to avoid confusion if someone else comes across this thread.

 

Evidently this forum doesn't supporting editing existing posts, so I can't change it, but my connection sheet has the pin #s and colors of the CAS signals backwards.
I've changed my sheet so:

• Pin 2 is CAS G- 1P (L)
• Pin 3 is CAS G+ 1N (G)
• Pin 7 is CAS Ne- 1Q (W)
• Pin 24 is CAS Ne+ 1T (R)

Sorry for any confusion this has caused. I'm on my way to change my MS right now.